Clinical, histological and serological data of 72 patients with antimitochondrial antibodies (AMA) were analyzed. 56 (78%) of the patients exhibited chronic cholestatic hepatopathy; in 30 of these primary biliary cirrhosis (PBC) was diagnosed and in 26 "possible PBC". The remaining 16 patients were subsumed in an "other illness' group. A collagen or autoimmune disease was found in 8 patients of the chronic cholestatic hepatopathy group and in 3 of the "other illness" group. Histological findings were diagnostic for PBC or cirrhotic liver in 90% of the patients with clinical signs, while 64% of the symptomfree patients had unspecific histological liver alterations. In general, increasing serum IgM, alkaline phosphatase, gamma-GT and symptoms paralleled increasing AMA titers, although asymptomatic patients with high AMA titers were also seen. The prevalence of hepatopathies rose with increasing AMA titers, but otherwise no association of AMA titers and diagnosis was observed. Therefore, a positive AMA test bears out suspicion of hepatopathy, but cannot be regarded as specific for PBC when other liver signs are absent.